Adsorption of Quaternized-chitosan-modified Reduced Graphene Oxide

A novel quaternized-chitosan-modified reduced graphene oxide(HACC-RGO) combined the adsorption advantages of RGO and 2-Hydroxypropyltrimethyl ammonium chloride chitosan(HACC). The adsorption property of HACC-RGO sheets for methyl orange(MO) was demonstrated and compared with RGO and HACC. The removal ratios of HACC-RGO sheets reached 92.6% for MO after a 24 h adsorption. The adsorption kinetics, isotherms and thermodynamics were investigated to indicate that the kinetics and equilibrium adsorptions were well-described by pseudo-second-order kinetic and Freundlich isotherm model, respectively. The thermodynamic parameters suggested that the adsorption process was spontaneous and endothermic in nature. Moreover, monodisperse HACC-RGO/CS beads were fabricated by the microfluidic method. The adsorption and desorption of HACC-RGO/CS beads for MO were studied. After three adsorptiondesorption cycles, the adsorption capacity remained above 55% and the desorption capacity was not below 70%. The HACC-RGO/CS beads can be reused and have great potential applications in removing organic dyes from polluted water.     

面向高效稳定钙钛矿太阳能电池埋底界面的推-拉型富勒烯二聚体设计（英文）

钙钛矿太阳能电池(PSCs)的界面接触缺陷是影响其性能的重要因素,会引发迟滞效应从而降低转换效率(PCE)并使器件运行稳定性恶化.界面材料通常被用于消除界面缺陷,然而设计兼具优越电荷传输和缺陷钝化能力的高效界面分子仍然面临挑战.本文研究了四种新型推-拉型富勒烯二聚体DC60–R1–R2 (R1=H或Cl, R2=H或MeO),并将其作为金属氧化物和钙钛矿之间的界面层.这些富勒烯二聚体之间的极性取代基决定了分子间的相互作用, DC₆₀–Cl–MeO由于其吸电子基团(–Cl)与给电子基团(–MeO)之间最强的电子推拉效应,表现出最佳的电荷传输和缺陷钝化能力. DC₆₀–Cl–MeO作为界面材料的未封装平面结构(FAPbI₃)_x(MAPbBr₃)_1-x PSC获得最高23.3%的PCE,且无迟滞现象,即使在高湿环境中储存500小时后仍能保持接近100%的初始效率.在一个太阳光强度下,无需任何封装或者惰性气体保护,钙钛矿太阳能电池在最大功率点连续运行的外推T